A very promising new method for phase contrast imaging is based on the Talbot method. This does not require an expensive synchrotron as in previous known methods; rather, a conventional X-ray tube can be used. A description of the method may be found, for example, in the document U.S. Pat. No. 7,564,941 A1. In the method, various gratings which require a very small spacing of the individual bars of only a few micrometers, and furthermore a high aspect ratio, are inserted into the beam path. The production of such gratings represents a great challenge, for which there are not yet any solutions without disadvantages. One known studied technique is based on the LIGA method, the German acronym LIGA standing for the steps Lithographie, Galvanik, Abformung (Lithography, Electroplating, Molding). This method, which is described in the document DE 41 07 662 A2, is however very elaborate. An alternative method is based on the etching of porous silicon. This method is described for example in the document DE 100 47 664 A1, but is still in the test phase.